Hat sizer



FIG. 1 is a front perspective view of a hat sizer showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front elevation view of my design, the opposite side being a mirror image;

FIG. 4 is a top elevation view thereof, the opposite side being a mirror image; and,

FIG. 5 is a side elevation view thereof, the opposite side being a mirror image.

The broken line showing of a hat is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a hat sizer, as shown and described. 